1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method and, more particularly, to an image processing apparatus and an image processing method to prevent a transitional phenomenon from occurring when an image is changed.
2. Description of the Related Art
An image processing apparatus, such as a TV, receives an image signal containing a predetermined signal in the form of an air wave TV broadcast, a cable TV broadcast etc., from broadcast stations, or receives an image signal inputted by various video apparatus such as a VCR or a DVD player and performs image processing on the image signal to display image. The image processing apparatus may comprise a light source generating light to display the image. The image processing apparatus having the light source may include a projection TV, LCD TV, etc.
FIG. 1 is a block diagram schematically showing the composition of a conventional image processing apparatus comprising a light source. The image processing apparatus 1 may be a DLP (digital light processing) type projection TV, and comprises a light source 11, a displaying part 12, an image processing part 13, a display driving part 14 and a controlling part 15. The light source 11 generates light for an image display. The displaying part 12 may be a screen which displays an image. The image processing part 13 performs predetermined image processing including analog-to-digital conversion, decoding, etc. on the image signal received from the broadcasting station or the video apparatus.
The display driving part 14 comprises a DMD (digital micromirror device) having an array of a plurality of micromirrors, and drives each micromirror on the basis of the image signal. The display driving part 14 adjusts the intensity of the light generated by the light source 11 to display an image on the displaying part 12. The controlling part 15 performs the overall control of the image processing apparatus 1, and controls the image processing part 13 and the display driving part 14 to display the image according to a channel or a source which is chosen by a user.
According to the image processing apparatus 1, if the channel or the source which has been displayed is changed into another channel or source, the image which is being changed is controlled not to be displayed. For example, if there is an order from the user that the channel or the source should be changed, the image processing apparatus 1 transmits a video mute signal not to display any image to the display driving part 14, and controls the image processing part 13 to convert to the channel or the source which is chosen by the user. If the image processing apparatus 1 determines that the channel has been changed by checking the image processing part 13, it transmits a video mute cancellation signal to the display driving part 14, so that the image from the changed channel or source may be displayed on the displaying part 12.
However, according the conventional image processing apparatus 1, if there is not synchronization between the time when the video mute is performed and the time when the channel or the source is changed by a predetermined cause, an unstable image may be displayed on the displaying part 12. That is, when the video mute is cancelled even though the change of the channel or the source has not been completed, the changing image between channels or sources is displayed, so that broken image may be shown by a transitional phenomenon.